• 대한치과보철학회지
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• 제45권2호
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• pp.191-202
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• 2007

Statement of problems: Long-term success of esthetic restorations, depends on various factors, especially on color stability of the restorations. The color stability is affected by resin cements beneath the porcelain laminate veneers. Purpose: The purpose of this study was to comprehend the color stability of resin cements by comparing with 4 different kinds of resin cements (Choice, Variolink II, Nexus 2, Rely-X). Material and methods: Porcelain laminate disk samples were luted with resin cements. After thermocycling of each 1000, 2000 and 3000 cycle, specimens were measured by spectrophotometers and the color differences were. Results: 1. After thermocycling of 1000, 2000 and 3000cycle, color difference, $({\Delta}E^*)$ of all specimens were incresed, but were not statiscally significant differences. 2. In the Choice of A1 shade and the Nexus 2 of A3 shade, color difference$({\Delta}E^*)$ after thermocycling of 3000cycle was $incre^*ased$ significantly than after thermocycling of 1000cycle. However, other groups did not show any statistically significant differences (P<0.05). 3. After thermocycling of 3000cycle, color difference$({\Delta}E^*)$ between A1 shade and A3 shade of Nexus 2 showed statistically significant difference. However no statistically significant differences were observed in other groups (P<0.05). 4. The mean of color difference$({\Delta}E^*)$ is 1.0-2.06 after 3000 thermocycling and the data were ranked in the ascending order of Variolink II, Nexus 2, Choice and Rely-X in A1 shade group and Choice, Rely-X, Variolink II and Nexus 2 in A3 shade group. Conclusion: Above results revealed that, after 3000 thermocycing, the color difference $({\Delta}E^*)$ of experimental resin cements was within clinically acceptable ranges. Color stability of 4 different resin cements was comparatively excellent.

• 구강회복응용과학지
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• 제23권1호
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• pp.79-84
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• 2007

Mineral Trioxide Aggregate(MTA) has been used in Endodontic treatment successfully for more than 10 years. But the high cost of MTA limits its use in endodontics in Korea. Recently many studies have been done to compare MTA and Portland cements. To investigate the chemical constitutions of MTA (Proroot MTA, Tulsa Dental), Gray Portland cement (Lafarge Halla cement), White Portland cement(Union corp), and fast setting cement (SSangyong cement), we performed SEM(scanning electron microscope)(S4700, Hitachi) examination and EDS(Energy dispersive spectrometry)(emax, Horiba) analysis. SEM examination and EDS analysis were committed to and performed in SNU DRI (Seoul National University Dental Research Institute). We found that particles of MTA were relatively round, uniform in size, and compactly packed compared to Portland cements. Chemical constitutions of MTA, GPC, WPC and FSC were similar. It was shown that MTA contains much BiO2 . MTA and WPC showed less heavy metals such as Fe and Mg compared to GPC and FSC. FSC showed remarkably high aluminum content.

• The Journal of Advanced Prosthodontics
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• 제9권6호
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• pp.447-452
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• 2017

PURPOSE. To evaluate the sealing performance of Hybrid Coat and its influence on the shear bond strength of five dentin surface cements. MATERIALS AND METHODS. Six premolars were pretreated to expose the dentin surface prior to the application of Hybrid Coat. The microscopic characteristics of the dentinal surfaces were examined with scanning electron microscopy (SEM). Then, 40 premolars were sectioned longitudinally, and 80 semi-sections were divided into a control group (untreated) and a study group (treated by Hybrid Coat). Alloy restoration was bonded to the teeth specimen using five different cements. Shear bond strength was measured by the universal testing machine. The fracture patterns and the adhesive interface were observed using a stereomicroscope. RESULTS. SEM revealed that the lumens of dentinal tubules were completely occluded by Hybrid Coat. The Hybrid Coat significantly improved the shear bond strength of resin-modified glass ionomer cement (RMGIC) and resin cement (RC) but weakened the performance of zinc phosphate cement (ZPC), zinc polycarboxylate cement (ZPCC) and glass ionomer cement (GIC). CONCLUSION. Hybrid Coat is an effective dentinal tubule sealant, and therefore its combined use with resin or resin-modified glass ionomer cements can be applied for the prostheses attachment purpose.

• 콘크리트학회논문집
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• 제12권5호
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• pp.111-120
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• 2000

In case of constructing concrete structure under water, generally concrete mixed with antiwashout admixture, high range water reducer, or AE-water reducing agent etc has been manufactured to ensure the quality of antiwashout underwater concrete because of being difficulty in ascertaining construction situation by the naked eye. The properties of high quality antiwashout underwater concrete that were aimed at affluent fluidity, workability and the compressive strength of 450 kgf/$\textrm{cm}^2$ at 28 ages using two types of blended cements are following as;(1) Setting time of antiwashout underwater concretes using blended cements was more greatly delayed than that of control concrete, however, was satisfied with criteria value of "Quality standard specification of antiwashout admixture for concrete".(2) As a test results of slump flow, efflux time and box elevation of head, it was found that workability of high quality antiwashout underwater concrete was improved. (3) Heat evolution amount of OPC was 1.5 times as high as that of two types of bended cements in 72 hours. (4) Suspended solids of antiwashout underwater concrete using blended cements was more than that of control concrete, also compressive strength of high quality antiwashout underwater concrete was very low in early age, but was better than that of control concrete as to increasing ages.

• 대한치과보철학회지
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• 제30권3호
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• pp.437-443
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• 1992

This study was performed to investigate the availability of adhesive resin cement for luting agent of cast crown. The resin cements used in this study were Panavia-Ex(Kuraray Co., Japan) and C & B-Metabond (Parkell Bio-Materials U.S.A.). Zinc phosphate cement was Flecks zinc cement(Mizzy Inc., U.S.A.) The film thickness of cast crown at gingival margin, lateral wall and occlusal surface was observed with measuring microscope(Modek MXT 70 Matsuzawa Seiki Co., Japan) and the retention of cast crown was measured with Instron Universal Test Machine (Instron Engineering Co., U.S.A.) The results were as follows : 1. The value of retention of cast crown was the highest in the use of Panavia-EX, followed by C & B-Metabond and 2inc phosphate cement, respectively. 2. There was no difference in film thickness among the three cements, but the film thickness in all cements was highest at occlusal surface.

• The Journal of Advanced Prosthodontics
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• 제9권2호
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• pp.85-92
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• 2017

PURPOSE. The aim of this study was to evaluate the effect of tooth surface pre-treatment steps on shear bond strength, which is essential for understanding the adhesive cementation process. MATERIALS AND METHODS. Shear bond strengths of different cements with various tooth surface treatments (none, etching, priming, or etching and priming) on enamel and dentin of human teeth were measured using the Swiss shear test design. Three adhesives (Permaflo DC, Panavia F 2.0, and Panavia V5) and one self-adhesive cement (Panavia SA plus) were included in this study. The interface of the cement and the tooth surface with the different pre-treatments was analyzed using SEM. pH values of the cements and primers were measured. RESULTS. The highest bond strength values for all cements were achieved with etching and primer on enamel ($25.6{\pm}5.3-32.3{\pm}10.4MPa$). On dentin, etching and priming produced the highest bond strength values for all cements ($8.6{\pm}2.9-11.7{\pm}3.5MPa$) except for Panavia V5, which achieved significantly higher bond strengths when pre-treated with primer only ($15.3{\pm}4.1MPa$). Shear bond strength values were correlated with the micro-retentive surface topography of enamel and the tag length on dentin except for Panavia V5, which revealed the highest bond strength with primer application only without etching, resulting in short but sturdy tags. CONCLUSION. The highest bond strength can be achieved for Panavia F 2.0, Permaflo DC, and Panavia SA plus when the tooth substrate is previously etched and the respective primer is applied. The new cement Panavia V5 displayed low technique-sensitivity and attained significantly higher adhesion of all tested cements to dentin when only primer was applied.

• Restorative Dentistry and Endodontics
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• 제41권3호
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• pp.167-175
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• 2016

Objectives: Endodontically treated teeth with insufficient tooth structure are often restored with esthetic restorations. This study evaluated the cytotoxicity and biological effects of yttria partially stabilized zirconia (Y-TZP) blocks in combination with several dental cements. Materials and Methods: Pairs of zirconia cylinders with medium alone or cemented with three types of dental cement including RelyX U200 (3M ESPE), FujiCEM 2 (GC), and Panavia F 2.0 (Kuraray) were incubated in medium for 14 days. The cytotoxicity of each supernatant was determined using 3-(4,5-dimethylthiazole- 2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays on L929 fibroblasts and MC3T3-E1 osteoblasts. The levels of interleukin-6 (IL-6) mRNA were evaluated by reverse transcription polymerase chain reaction (RT-PCR), and IL-6 protein was evaluated by enzyme-linked immunosorbent assays (ELISA). The data were analyzed using one-way ANOVA and Tukey post-hoc tests. A p < 0.05 was considered statistically significant. Results: The MTT assays showed that MC3T3-E1 osteoblasts were more susceptible to dental cements than L929 fibroblasts. The resin based dental cements increased IL-6 expression in L929 cells, but reduced IL-6 expression in MC3T3-E1 cells. Conclusions: Zirconia alone or blocks cemented with dental cement showed acceptable biocompatibilities. The results showed resin-modified glass-ionomer based cement less produced inflammatory cytokines than other self-adhesive resin-based cements. Furthermore, osteoblasts were more susceptible than fibroblasts to the biological effects of dental cement.

• 공업화학
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• 제29권4호
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• pp.399-404
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• 2018

타이어 트레드 컴파운드와 천연 및 합성 고무 접착제 종류에 따른 가황 전/후의 점착력과 접착력 차이를 비교하였다. 가황 전 점착력은 모든 트레드에서 천연고무 시멘트가 가장 강하고, 시간의 경과에 따른 점착력 감소도 천연고무 시멘트가 합성고무 시멘트보다 낮았다. 가황 전 점착력은 시멘트에 사용된 고무의 유리전이온도에 영향을 받았으며, 천연고무가 합성고무에 비해 시간의 경과에 따른 점착력 감소도 적었다. 가황 후 접착력은 천연고무 시멘트가 천연고무가 주성분인 트레드에 강하게 접착하지만 합성고무가 주성분인 트레드에는 약하게 접착했다. 반면 유화중합 SBR, 용액중합 SBR 시멘트는 모든 트레드 컴파운드에 강하게 접착하였고, 시멘트 고무의 가황 속도가 느릴수록 강한 접착력을 보였다.

• Restorative Dentistry and Endodontics
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• 제18권2호
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• pp.507-513
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• 1993

본 연구의 목적은 3종의 일반적 glass ionomer cement과 1종의 광중합형 glass ionomer cement을 자료로 하여 연화후 3, 5, 7, 10분 경과시켜 methylene blue용액에 침적하여 그침투를 측정하여 물의 영향을 관찰하고 이상의 시간과 관련하여 수분과 접촉시 그 용해도를 zinc phosphate와 polycarboxylate cement와 비교관찰하였다. blue stained zone은 모든 glass ionomer cement에서 나타났고 inner opaque zone은 두종의 regular glass ionomer cement에서만 나타났다. 연화시작부터 물에 침적시키는 사이시간이 연장되매 따라 모든 cement에서 두 zone의 후경이 감소하였고 regular glass ionomer cement의 면으로 부터 물질의 손실량은 현저히 감소하였으며 물질의 손실량에 대해서는 light curing glass ionomer cement는 시간에 거의 영향을 받지 않았으며 zinc phosphate cement파 polycarboxylate cement도 이와 유사성을 보였다.

• Restorative Dentistry and Endodontics
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• 제38권4호
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• pp.234-240
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• 2013

Objectives: This study evaluated the effects of intraradicular moisture on the pushout bond strength of a fibre post luted with several self-adhesive resin cements. Materials and Methods: Endodontically treated root canals were treated with one of three luting cements: (1) RelyX U100, (2) Clearfil SA, and (3) G-Cem. Roots were then divided into four subgroups according to the moisture condition tested: (I) dry: excess water removed with paper points followed by dehydration with 95% ethanol, (II) normal moisture: canals blot-dried with paper points until appearing dry, (III) moist: canals dried by low vacuum using a Luer adapter, and (IV) wet: canals remained totally flooded. Two 1-mm-thick slices were obtained from each root sample and bond strength was measured using a push-out test setup. The data were analysed using a two-way analysis of variance and the Bonferroni post hoc test with p = 0.05. Results: Statistical analysis demonstrated that moisture levels had a significant effect on the bond strength of luting cements (p < 0.05), with the exception of G-Cem. RelyX U100 displayed the highest bond strength under moist conditions (III). Clearfil SA had the highest bond strength under normal moisture conditions (II). Statistical ranking of bond strength values was as follows: RelyX U100 > Clearfil SA > G-Cem. Conclusions: The degree of residual moisture significantly affected the adhesion of luting cements to radicular dentine.